Writing instrument



April 28, 1964 J. M. KAHN ETAL 3,130,712

WRITING INSTRUMENT Filed March 4, 1960 2 Sheets-Sheet 1 FIG.|

FIG.6

INVENTOR}; JULIUS M. KAHN MORRIS LEVY MKM) ATTORNEYS April 28, 1964 J. M. KAHN ETAL 3,130,712

- WRITING INSTRUMENT Filed March 4, 1960 2 Sheets-Sheet 2 INVENTOR? JULIUS-M. KAHN MORRIS LEVY BYWQMT ATTORNEYS United States Patent 3,130,712 WRITING INSTRUMENT Julius M. Kahn, Englewood Clifis, and Morris Levy, Teaneck, N.J., assiguors to David Kahn, Inc., Hudson County, N.J., a corporation of New Jersey Filed Mar. 4, 1960, Ser. No. 12,797 3 Claims. (Cl. 120-42.13)

This invention relates to a writing instrument and more particularly to a writing instrument provided with a plurality of spaced writing cartridges selectively slidable through the lower end of a barrel into writing position.

More specifically, according to one aspect of the present invention, there is provided a writing instrument comprising a barrel having an upper end and a lower end, a plurality of spaced writing cartridges selectively slidable through the lower end of the barrel into writing position, means for selectively moving each of the cartridges into projected writing and non-writing positions and means within the barrel dividing the interior of the barrel into a plurality of longitudinal chambers of non-circular cross section for receiving the cartridges. At least a portion of the cartridges have a non-circular cross sectional shape which cooperates with the non-circular cross sectional shape of the chambers for maintaining the cartridges substantially non-rotatable. There are also provided resilient means for urging the cartridges against the inner surface of the barrel and means to releasably lock each cartridge against upward movement when in a projected writing position.

More specifically, the means within the barrel comprises a spacer assembly which is generally coaxial with the barrel, the assembly having a plurality of radial wings which divide the interior of the barrel into the chambers. Adjacent wings of the spacer assembly define between them a dihedral angle and the rear of the cartridges comprises surfaces which also define a dihedral angle, the dihedral angle of the surfaces being preferably approximately equal to the dihedral angle defined by the wings. In order for the front of the cartridge to fit snugly against the interior of the barrel, the front of the cartridge preferably comprises an arcuate surface having radius of curvature approximately equal to the radius of curvature to the interior of the barrel.

According to the preferred aspect of the invention, the means for releasably locking each cartridge against upward movement is constituted by providing the barrel with a plurality of circumferentially spaced openings therethrough, preferably longitudinally extending slots, and providing each cartridge with an outwardly extending detent on the front thereof, the detent of the cartridge being received within the corresponding opening when the cartridge is in the projected writing position to thereby releasably lock the cartridge against upward movement.

Each cartridge is also preferably provided with an outwardly extending projection axially aligned with the detent, each projection extending through its respective slot and providing means whereby each cartridge can be selectively moved into writing and non writing positions. The invention is not only directed to the combination of the writing instrument and the cartridges, but also to the cartridges per se. According to the preferred form of the invention, the cartridge is made of organic plastic material whereby the cartridge can be easily produced by a molding operation. The use of a plastic cartridge also permits the fabrication of the barrel from relatively soft material such as aluminum since the sliding action of the cartridges against the aluminum wall will not abrade, cut or scratch the aluminum.

' Although, as will be hereinafter described, the present I invention is not limited to any particular type of writing instrument, it is preferably directed to a multi-color pen wherein each of the cartridges has at one end thereof a ballpoint writing tip, the cartridges being hollow and forming a reservoir for the writing fluid. Other aspects, advantages, and objects inherent in the present invention will be readily apparent from the following description with reference to the accompanying drawings in which:

FIGURE 1 is a vertical sectional view, with certain parts broken away, of a multi-color ballpoint pen showing one of the ink cartridges in the retracted or non-writing position.

FIGURE 2 is a view similar to FIGURE 1 but showing one ink cartridge in its projected or writing position.

FIGURE 3 is a sectional view in line 3-3 of FIGURE 1 showing the central spacer assembly for holding the ink cartridges in their relatively spaced positions.

FIGURE 4 is a similar sectional view taken on line 44 of FIGURE 1 showing the springs on the central spacer assembly holding the ink cartridges against the inner surface of the barrel of the pen.

FIGURE 5 is a detailed cross section taken on line 55 of FIGURE 1 showing the mating relationship of the parts of the central spacer assembly, the ink cartridges being omitted in this view.

FIGURE 6 is a perspective view partly in section of an ink cartridge of the present invention.

FIGURE 7 is a detailed view partly in section showing one of the cartridges engaging the barrel in the retracted position.

FIGURE 8 is a view similar to FIGURE 7 showing how the cartridge is moved from the retracted position to the projected position by manual pressure.

FIGURE 9 is a detailed fragmentary view partly in section showing the cartridge in the projected position with the detent engaged in the slot of the barrel for holding the ink cartridge in the projected position.

FIGURE 10 is an elevational view of one of the component springs of the central assembly for holding the ink cartridges in their relatively spaced positions, this view being taken in the direction indicated by arrow A of FIG- URE 3.

FIGURE 11 is an elevational view of two of the component springs of the spacer assembly, this view being taken in the direction of arrow B of FIGURE 3.

Referring to FIGURES 1 and 2 of the drawing the writing instrument comprises a hollow cylindrical barrel It] provided with a frustoconical end 11 having an axial aperture 12 therein. The barrel has near the upper end thereof a plurality of circumferentially spaced openings 13 therethrough, the openings preferably being longitudinally extending slots as shown in the drawing. Positioned about the open rear end 14 the barrel is a cap 15 removably frictionally secured to the upper end of the barrel to provide a closure for the barrel, the cap optionally provided with a spring clip 16 thereon. The longitudinally extending slots 13 are preferably 3 in number and are equidistantly spaced circumferentially of the barrel, the slots extending upwardly from slightly above the midsection for about one-quarter of the barrel length.

Mounted in the barrel are a plurality of writing cartridges 17, each cartridge (see FIGURE 6) comprising a cartridge body 18 having a longitudinal bore 19 therein extending from the lower end of the body and terminating near the upper end thereof. A ballpoint writing tip 20 is secured in the bore in the lower end of the body 18 in any conventional manner such as by force fitting. The bore 19 in the cartridge body defines the reservoir for the writing fluid, the reservoir being vented to the atmoshere by transverse bore 21, communicating with the bore 19 near its upper end.

On the front of the cartridge there is intermediate the ends of the body 18 a laterally extended serrated projection 22. On the same side of the body 18 near the upper end thereof there is a laterally extending detent 23, the detent being defined by side Walls 24, upper surface 25, lOwer surface 26, and front surfaces 27 and 28. The upper and lower surfaces and 26 are preferably at right angles to the axis of the cartridge. The lower front surface 27 is preferably upwardly and outwardly inclined so as to form a camming surface for a purpose hereinafter described. At the extremity of the cartridge there is a finger lug 29 having a lower edge 30 and side walls 31. The front surface of the cartridge is upwardly and inwardly inclined at 32 so that the front surface 33 of the finger lug 29 is positioned inwardly of the front surface of the cartridge below the detent 23. In the preferred construction the body 18 of the cartridge also has a particular cross sectional shape which will subsequently be discussed in detail.

Referring particularly to FIGURES 3, 4, 5, 10 and 11 there is positioned in the interior of the barrel 10 a central spacer assembly shown generically by reference numeral 42. The spacer assembly comprises three substantially identical spring members 35 each having a main body portion 35A formed in two halves, defining between them a dihedral angle of slightly greater than 120. The two halves are separated from approximately the midsection downwardly along a out line at 36 which is coincident with the apex line of the dihedral angle. These separated portions are also cut away along their outer edges 37 to form two downwardly extending relatively convergent spring lobes 38. The tips of these spring lobes are bent outwardly at 39 to form fingers for engaging the ink cartridges 17. One-half of each spring element has a hole 40 at approximately its center and the other half has a symmetrically positioned protuberance 41. The three spring elements 35, when positioned with half of one abutting the half of another at their outer edges, with the protuberance 41 on one half positioned in the hole 40 on a half of another element, as shown more clearly in FIGURE 5, form a nested assembly, the apices of the main body portions 35A being spaced apart as the corners of an equilateral triangle symmetrically positioned with respect to the axis of the pen due to the greater than the 120 divergence of the two halves of each spring member. This construction provides for greater flexibility in assembly and use than a close nested assemblage. This nested assemblage, force-fitting within the hollow pen barrel 10 is preferably positioned somewhat below the mid-section of the longitudinal slots 13 therein. In such position the finger tips 39 on the pair of spring lobes 33 of each spring element contact an ink cartridge 17 to resiliently urge the cartridge against the inner surface of the barrel 10 as shown in FIGURES 1, 4, and 8.

The resilient spacer assembly 42 may therefore be considered as having a plurality of radial wings, the wings being defined by the main body portions 35A, dividing the interior of the barrel into a plurality of longitudinal chambers of non-circular cross section for receiving the cartridges 17. Because of the resilient action of the finger tips 39, the cartridges are urged against the inner surface of the barrel and frictionally constrain the cartridges in their sliding movement.

In the preferred construction the cartridges 17 also have a non-circular cross sectional shape. The rear of the cartridge preferably comprises longitudinally extending surfaces 43 and 44 which define between them a dihedral angle. This angle is preferably approximately equal to the dihedral angle between the wings of the spacer assembly 42 and in the preferred construction the dihedral angle between surfaces 43 and 44 is approximately 120. It will be appreciated that the dihedral angle between surfaces 43 and 44 may be slightly greater or slightly less than the dihedral angle between the wings of the spacer assembly 42, it being only necessary for the angles to be suificiently similar so that the rear of the cartridge can be received or nested in the angle defined by the wings. It is also apparent that since the rear of the cartridge is nested between the wings that the engagement between the surfaces of the cartridge and the surfaces of the wings will substantially prevent rotation of the cartridges about their axes.

In order to enable utilization of the large portion of the volume of the chambers 45 for the cartridges and to provide the cartridges with a maximum surface area contacting the inner surface of the barrel, the front of the cartridge 17 comprises arcuate surface 46 having radius of curvature approximately equal to the radius of curvature of the interior of the barrel. The periphery of the cartridge 17 also includes side surfaces 47 which may be of any depth. It is evident that the significant surfaces which define the periphery of the cartridge are surfaces 43, 44 and 46. These may be considered as generally defining a sector of a circle, the side surfaces 47 are not being considered.

The rear of the cartridge, or the inward side, is upwardly and outwardly inclined as shown at 48, the inclination beginning at a point between the projection 22 and the detent 23 so that the surfaces of the rear of the cartridge as shown as 48 all lie in front of the rear of the cartridge below inclined portion 48. The purpose of this inclined portion will be described hereinafter.

The upper end of the barrel is provided with one or more outstruck or fluted sections 49, preferably three in number and aligned with the slots 13. These fluted portions 49 serve to frictionally engage the cap 15 so that the cap 15 is securely held on the end of the barrel. It is pointed out that a cap 15 serves to close the open rear end of the barrel 14 and is only removed when it is necessary to change or replace a cartridge 17 According to the preferred construction there are provided three cartridges 17, each one containing a different color ink. In order to identify the color ink within the cartridge at least a portion of the front of the cartridge is colored corresponding to the color of the ink within the cartridge. The portion of the cartridge which is colored preferably comprises the serrations on projection 22, the portion between projection 22 and detent 23, and the portion immediately below projection 22 for a distance about equal to the length of the slot. Alternatively, when, as in the preferred modification, the cartridge is of plastic, the entire body of the cartridge may be colored corresponding to the color of the ink within the cartridge.

To assemble the pen each cartridge 17 is inserted point downwardly in its respective chamber 45 through the open rear end of the barrel 14 until the projection 22 is received within its respective slot 13. In this position the springs of the spacing member urge the cartridges 17 against the inner surface of the barrel as shown more clearly in FIGURES 1 and 7. According to the preferred construction of the lower edge 26 of the detent 23 is seated on the upper edge of the barrel as shown in FIGURE 7. This positioning of the lower edge 26 on the upper edge of the barrel prevents the cartridge from sliding forwardly. It is pointed out, however, that it is not necessary for the lower edge 26 of the detent to be seated against the upper edge of the barrel when the cartridges are in the retracted position since the spring pressure of the spacing means is alone sulficient to prevent the cartridge 17 from sliding downwardly of its own accord. When the cartridges 17 are positioned in the barrel in the retracted position with the detent near the upper end of the barrel, the projection 22 is near the upper end of the slot 13. When it is desired to write with any particular color ink the finger of the user is applied to the projection 22 of a selected cartridge, as shown in FIGURE 8, to force the cartridge inwardly to disengage lower edge 26 of the detent from the upper edge of the barrel. Then, with the finger still on projection 22, the cartridge is urged toward the lower end of the barrel until the detent 23 is received in slot 13 as shown in FIGURE 9. When the finger pressure is re leased the resilient action of the spacing means again urges the cartridge against the inner wall of the barrel so that the upper edge 25 of the detent 23 is positioned under the upper edge of the slot 13. This locks the cartridge in the writing position to prevent upward movement of the cartridge when writing with the pen. The camming surface 27 on the detent 23 assists in urging the cartridge inwardly when finger pressure is applied by sliding along the rear extremity of the upper end of the barrel. The barrel and cartridges are so dimensioned that only one cartridge may be in the projected writing position at any one time.

When it is desired to retract the cartridge to the retracted position wherein the writing tip is concealed with the barrel, finger pressure is applied to the projection 22 in the position shown in FIGURE 9 to again urge the cartridge inwardly of the barrel so as to disengage the upper end 25 of the detent from the upper edge of the slot and to thereby permit the cartridge to be moved upwardly. In the projected position the cartridge is at an angle to the axis of the pen as shown in FIGURES 2 and 9, the angular position of the cartridge being assisted by the fact that the front surface of the finger lug 29 is positioned inwardly of the front surface of the cartridge below detent 23.

When the ink in one of the cartridges becomes exhausted the cartridge may be replaced by removing the cap 15 from the rear end of the barrel and inserting a finger nail under finger lug 29 to urge the rear extremity of the cartridge inwardly until the projection 22 is no longer engaged with slot 13. The inclined area 48 at the rear end of the cartridge provides additional clearance to enable the cartridge to be moved inwardly sufficiently to disengage the projection 22 from slot 13.

It will be noted that, while the invention has been described with respect to three ink cartridges which could, for instance, contain red, blue and green ink, it is also within the contemplation of the invention to use a greater or lesser number, as for example four or two. In either case corresponding changes will be made in the number of longitudinal slots 13 and the spring elements 35 would be greater or fewer in number to divide the barrel into more or less chambers 45. Of course, the dihedral angle between the halves of the spring elements 35 and the dihedral angle of the rear of the cartridge would be correspondingly changed.

It will be understood that, while the operation of the pen has been described with respect to the operation of only one ink cartridge member, the operation will be identical with respect to the others.

The term cartridge used in the claims is intended broadly to cover a holder member having a fluid reservoir therein or a holder member for a crayon or pencil, it being understood that the structure herein set forth can be used in connection with a solid Writing medium or a fluid writing medium.

According to the preferred form of the invention the cartridge body is molded in one piece from an organic plastic material such as nylon (synthetic linear polyamid), polyethylene, polypropylene, or other organic plastic material. The enumerated plastics are preferred because these have a relatively low coefficient of friction and that therefore slide easier in the barrel. The production of the cartridge body from plastic materials is particularly desirable because it enables the barrel to be constructed from relatively soft materials such as aluminum or plastics, for example. If the cartridge, and especially the upper end thereof including the projection 22 and detent 23, are made of metal, the continual sliding action of the metal cartridge against the inner surface of the barrel will cut, scratch or abrade a soft metal such as aluminum or other soft materials such as plastics. Metal as used herein includes pure metals and metal alloys. Therefore, the barrel of the writing instrument,

when using a metal cartridge, could not be constructed of aluminum and similar materials.

In the preferred form of the invention as previously described the body of the cartridge has a non-circular cross sectional shape which cooperates with the shape of the chambers to maintain each cartridge substantially non-rotatable within its chamber. If the cartridge has a circular cross section there is a constant tendency for the cartridge to rotate. This rotation frequently causes the projection 22 or detent 23 to become disengaged from the slot rendering it necessary to readjust the cartridge. Additionally, when the cartridge has a circular cross section the person assemblying the pen may insert the cartridge so that the projection 22 and detent 23 are not aligned with the slot. The use of a cartridge having the shape as herein described eliminates these problems.

It is apparent that when a cartridge is made of plastic as herein described the entire cartridge, except for the Writing tip, can :be made in one piece. This greatly reduces the production cost and eliminates assembly operations. For example, if [the reservoir portion of the cartridge is made from tubular metallic stock having a circular cross section, the projection 22, the detent 23 and the finger lug 29 would be formedon a separate piece of metal stock, which would be a flat piece of metal in the shape of a bar. The bar would be inserted in the open, rear end of the tubular reservoir, the reservoir being vented by passageways defined by the space between the end of the bar inserted in the reservoir and the inner walls of the reservoir. Such passageways must of necessilty be larger in cross section than the vent 21, as shown in FIGURE 6, and therefore there would be a much greater tendency for the cartridge to leak when the pen is maintained with the point upward over a relatively long period of time. In addition, the metal bar must be carefully fitted in the open, upper end of the reservoir and this requires another assembly operation. These shortcomings are overcome by making the cartridge in one piece as herein described. It is also apparent that in the described construction the reservoir portion of the cartridge can extend upwardly above the projection 22 and this provides the cartridge with a greater ink capacity than can be obtained when a metal bar, having the projection 22 and detent 22 thereon, is inserted in the upper end of the reservoir since in the latter case the reservoir must terminate below the projection of the bar.

We claim:

1. In a writing instrument, a 'barrel having an open upper end, a lower end, and provided with a plurality of spaced writing cartridges selectively slidable through the lower end of the barrel into writing position, said cartridges comprising organic plastic material, a spacer assembly within and generally coaxial with said barrel, said assembly having plurality of radial wings dividing the interior of the barrel into at least three chambers of substantially similar non-circular cross section for receiving the cartridges, adjacent wings defining between them a dihedral angle, the rear of each cartridge having surfaces defining a dihedral angle approximately equal to the dihedral angle defined by said wings, said cartridges being positioned in said chambers with the rear of the cartridges nested in the angle defined by said wings to maintain the cartridges substantially non-rotatable, the front of each cartridge comprising an arcuate surface having radius of curvature approximately equal to the radius of curvature of the interior of the barrel, said spacer assembly including resilient means for urging said cantnid-ges against the inner surface of the barrel, said barrel being provided with a plurality of circumferentially spaced longitudinally extending slots therethrough, an outwardly extending detent on the front of each cartridge, said detent being received within one of said slots when said cartridge is in the projected writing position to releasably lock the cartridge against upward movement, an outwardly extending projection on the front of each cartridge axially aligned with the detent thereon, said projection extending through said slot and defining means for selectively moving each of the cartridges into Writing and non-writing positions, each of said cartridges being hollow, writing fluid Within the cartridges, and :a ballpoint writing tip at the forward end of each cartridge, the hollow of said organic plastic body portion being defined by a longitudinally extending bore extending from adjacent the writing tip upwardly beyond said laterally extending projection, said body portion having vent means therein for venting said bore to the atrnosphere.

2. A writing instrument cartridge comprising an elongated hollow organic plastic body portion having a ball point writing tip secured to the lower end thereof, writing fluid in the hollow of said body portion, the rear of at least a portion of said body portion being defined by longitudinally extending surfaces defining between them a dihedral angle, the front of the body portion being defined by a longitudinally extending arcuate surface, said body portion having a laterally extending projection and a laterally extending detent thereon, said detent and projection being axially aligned and integral with said body portion,

. 8 the hollow of said organic plastic body portion being defined by a longitudinally extending bore extending from adjacent the writing tip upwardly beyond said laterally extending projection, said body portion having vent means therein for venting said bore to the atmosphere.

3. A writing instrument cartridge according to claim 2, wherein said bore is a blind bore and said body portion has a transverse bore therein providing communication between said blind bore and the exterior of the cartridge, said transverse bore defining said vent means.

References Cited in the file of this patent UNITED STATES PATENTS 2,369,080 Schulman et a1 Feb. 6, 1945 2,624,315 Weisser et :al Jan, 6, 1953 2,676,570 Fahringer Apr. 27, 1954 FOREIGN PATENTS 808,421 Germany July 16, 1951 1,008,817 France Feb. 27, 1952 1,091,024 7 France Oct. 27, 1954 

1. IN A WRITING INSTRUMENT, A BARREL HAVING AN OPEN UPPER END, A LOWER END, AND PROVIDED WITH A PLURALITY OF SPACED WRITING CARTRIDGES SELECTIVELY SLIDABLE THROUGH THE LOWER END OF THE BARREL INTO WRITING POSITION, SAID CARTRIDGES COMPRISING ORGANIC PLASTIC MATERIAL, A SPACER ASSEMBLY WITHIN AND GENERALLY COAXIAL WITH SAID BARREL, SAID ASSEMBLY HAVING PLURALITY OF RADICAL WINGS DIVIDING THE INTERIOR OF THE BARREL INTO AT LEAST THREE CHAMBERS OF SUBSTANTIALLY SIMILAR NON-CIRCULAR CROSS SECTION FOR RECEIVING THE CARTRIDGES, ADJACENT WINGS DEFINING BETWEEN THEM A DIHEDRAL ANGLE, THE REAR OF EACH CARTRIDGE HAVING SURFACES DEFINING A DIHEDRAL ANGLE APPROXIMATELY EQUAL TO THE DIHEDRAL ANGLE DEFINED BY SAID WINGS, SAID CARTRIDGES BEING POSITIONED IN SAID CHAMBERS WITH THE REAR OF THE CARTRIDGES NESTED IN THE ANGLE DEFINED BY SAID WINGS TO MAINTAIN THE CARTRIDGES SUBSTANTIALLY NON-ROTATABLE, THE FRONT OF EACH CARTRIDGE COMPRISING AN ARCUATE SURFACE HAVING RADIUS OF CURVATURE APPROXIMATELY EQUAL TO THE RADIUS OF CURVATURE OF THE INTERIOR OF THE BARREL, SAID SPACER ASSEMBLY INCLUDING RESILIENT MEANS FOR URGING SAID CARTRIDGES AGANST THE INNER SURFACE OF THE BARREL SAID BARREL BEING PROVIDED WITH A PLURALITY OF CIRCUMFERENTIALLY SPACED LONGTIUDINALLY EXTENDING SLOTS THERETHROUGH, AN OUTWARDLY EXTENDING DETENT ON THE FRONT OF EACH CARTRIDGE, SAID DETENT BEING RECEIVED WITHIN ONE OF SAID SLOTS WHEN SAID CARTRIDGE IS IN THE PROJECTED WRITING POSITION TO RELEASABLY LOCK THE CARTRIDGE AGAINST UPWARD MOVEMENT, AN OUTWARDLY EXTENDING PROJECTION ON THE FRONT OF EACH CARTRIDGE AXIALLY ALIGNED WITH THE DETENT THEREON, SAID PROJECTION EXTENDING THROUGH SAID SLOT AND DEFINING MEANS FOR SELECTIVELY MOVING EACH OF THE CARTRIDGES INTO WRITING AND NON-WRITING POSITIONS, EACH OF SAID CARTRIDGES BEING HOLLOW, WRITING FLUID WITHIN THE CARTRIDGES, AND A BALLPOINT WRITING TIP AT THE FORWARD END OF EACH CARTRIDGE, THE HOLLOW OF SAID ORGANIC PLASTIC BODY PORTION BEING DEFINED BY A LONGTITUDINLLY EXTENDING BORE EXTENDING FROM ADJACENT THE WRITING TIP UPWARDLY BEYOND SAID LATERALLY EXTENDING PROJECTION, SAID BOYD PORTION HAVING VENT MEANS THEREIN FOR VENTING SAID BORE TO THE ATMOSPHERE. 